Shaft sinking apparatus



y 25, 1965 R. J. ROBBINS 3,185,226

SHAFT S INKING APPARATUS Filed March 17, 1959 7 Sheets-Sheet l INVENTORMay 25, 1965 R. J. ROBBINS SHAFT SINKING APPARATUS 7 Sheets-Sheet 2Filed March 17, 1959 INVENTOR. Rama .I EaZZl'M May 25, 1965 R. J.ROBBINS SHAFT SINKING APPARATUS 7 Sheets-Sheet 5 Filed March 17, 1959May 25, 1965 R. J. ROBBINS 3,185,226

SHAFT SINKING APPARATUS Filed March 17, 1959 7 Sheets Sheet 4 IN V ENTOR.

y 5, 1965 R. J. ROBBINS 3,185,226

SHAFT SINKING APPARATUS Filed March 17, 1959 7 Sheets-Sheet 6 22 IN V ENTOR.

A NEY May 25, 1965 R. J. ROBBINS SHAFT SINKING APPARATUS 7 Sheets-Sheet'7 Filed March 17, 1959 Mme/q United States Patent 3,185,226 SHAFTSINKING APPARATUS Richard James Robbins, 321 Grosvenor House, Seattle,Wash. Filed Mar. 17, 195?, Ser. No. 8%,098 Cim'ms. (Cl. 175-102) Thisinvention relates generally to mining and more particularly to animproved apparatus for excavating large diameter holes.

In the known methods and apparatus, for sinking mine shafts or the like,it is usually necessary to have available some type of entry or drift ata lower level which is connected to an adjacent existing shaft or otherentry which enables the cuttings material which is excavated in sinkingthe proposed mine shaft to be removed generally downwardly through thelower level to the adjacent existing shaft or entry and then raised ortaken to the surface. Another common method of excavating a mine shaftis to raise the proposed shaft from the lower existing level, drift orentry to the ground surface.

In shaft sinking operations wherein there is no existing lower level,drift or entry and the proposed mine shaft is to be excavated byadvancing the mine shaft bottom to a dead, great dificulty is had sincethe excavation and removal of the cuttings material generally take placein the same location.

It is the principal object of this invention to provide an improvedapparatus for excavating a generally vertical hole having a diameter ofat least approximately feet.

It is an object of this invention to provide an improved apparatus forsinking generally vertical mine shafts, or the like.

It is an additional object of this invention to provide an improvedapparatus for excavating holes in the ground which includes a flushingwater head to facilitate in the removal of cuttings material from thehole.

Another object of this invention is to provide an improved apparatus forsinking a mine shaft, or the like, wherein the mine shaft is advanced toa dead.

A further object of this invention is to provide an improved apparatusfor excavating a hole in the ground wherein a pilot hole is firstexcavated and then expanded substantially continuously from one end tothe other with the advancement of the pilot hole and the expansionthereof being generally in the same direction.

A still further object of this invention is to provide an improvedapparatus for sinking a mine shaft, or the like, which is economical incost, efficient in operation and reliable in use since there is a largesaving of both costs and lapsed time in using the improved method andapparatus.

A still further additional object of this invention is to provide animproved apparatus for sinking large diameter mine shafts, or the like,wherein an even, regular surface is left by the excavating action of theapparatus in comparison with such surface as normally left by blasting.Further, the mine shaft surface left by the apparatus in accordance withthis invention is not shattered, cracked or weakened as in the case ofnormally excavating the surface by blasting.

In order to overcome the disadvantages and objections to known andcommon methods and apparatus for excavating mine shafts, or the like,and in order to accomplish the desired objects as stated above, theimproved apparatus for excavating large diameter holes in the ground inaccordance with this invention contemplates first, excavating a pilothole either to the desired depth of the proposed shaft so that the pilothole extends substantially the entire distance or at least to a depthsufiicient to define a loading zone skip pocket, and then plac- "ice inga casing within the pilot hole with the casing being provided with aplurality of generally peripherally spaced openings. The casing extendsabove ground surface and defines an unloading zone or a skip dump and askipway shaft and a skip is positioned within the casing and suitablehoisting means is provided for hoisting the skip through the casing toground surface. The material which is generally outwardly disposedrelative to the casing is then removed by a suitable cutting and/ orconveying apparatus while maintaining the pilot hole in advance of theshaft working face with the cuttings material which is removed by thecutting and/ or conveying apparatus being passed through the openings inthe casing into the skip and then hoisted to the surface. The improvedmethod and apparatus enables a mine shaft, or the like, to be sunk to adead by first excavating material to establish the pilot hole byadvancing the pilot hole in a given direction and then effectivelyexpanding the pilot hole by excavating the material which is outwardlypositioned immediately adjacent the pilot hole with the advance of theexpansion being in substantially the same direction as the advance ofthe pilot hole. By maintaining the pilot hole beyond the shaft workingface a given distance, it is possible that the skip may be positionedwithin the advanced portion of the pilot hole, which defines a skippocket, so that the material may then be loaded into the skip andhoisted through the skipway shaft defined by the casing to the surface.The casing in effect amounts to a shaft so that there is no interferencein hoisting the cuttings material during the cutting and/ or conveyingaction of the apparatus which operates and is also positioned generallyoutwardly relative to the casing and which is supported by suitablemeans during the cutting and conveying operation thereof.

Other objects and important features of the invention will be apparentfrom a study of the specification following taken with the drawing,which together show, describe and illustrate :a number of preferredembodiments of the invention and what are now considered to be the bestmodes of practicing the principles thereof. Other embodiments may besuggested to those having the benefit of the teachings herein, and suchother embodiments are intended to be reserved as they fall within thescope and breath of of the subjoined claims.

In the drawing:

FIGURE 1 is a vertical sectional view of an embodiment of an improvedapparatus for performing a novel method for excavating a pilot hole foruse in sinking a mine shaft, or the like;

FIGURE 2 is an enlarged detailed sectional plan view taken along theline 22 of FIG. 1 looking in the direction of the arrows;

FIGURE 3 is a vertical sectional view, similar to FIG. 1, illustrating amodification of the improved apparatus which employs a novel method forexcavating the pilot hole in accordance with the teaching of thisinvention;

FIGURE 4 is an enlarged detailed sectional plan view showing a cutterdevice and valve means of the modification illustrated in FIGURE 3,taken along the line 4-4 looking in the direction of the arrows;

FIGURE 5 is an enlarged partial view illustrating the details of thecutter device and the valve means of FIG.

FIGURE 6 is a plan view of an embodiment of an improved apparatus forperforming a novel method for expanding a pilot hole in an operationsuch as sinking a mine shaft, or the like;

FIGURE 7 is an elevational view of the invention as illustrated in FIG.6;

FIGURE 8 is an enlarged partial elevational, view taken along the line8-8 of FIG. 7 looking in the direction of the arrows;

FIGURE 9 is an elevational view, similar to FIG. 7, of a modification ofthe improved apparatus employing a novel method for expanding a pilothole;

FIGURE 10 is an elevational view, similar to FIGS. 7 and 9, of a stillfurther modification of the improved apparatus which employs a novelmethod for expanding a pilot hole; 7 I

FIGURE ll is an elevational view of an embodiment of a head framestructure as used with the improved apparatus for performing the novelmethods of excavating and expanding a pilot hole in accordance with theteaching of this invention;

FIGURE 12 is an elevational view, similar to FIG. 11, of a modificationof such head frame structure, and

FIGURE 13 is a schematic illustration of the arrangement of therespective improved apparatus for perfornn ing the novel methods inexcavating and expanding a pilot hole used in an operation such assinking a mine shaft, or the like.

Attention is now directed to the drawing wherein there are illustratedseveral modifications of the apparatus for performing the improvedmethod of mining in accordance with this invention and which furtherillustrates the improved method and the preferred modifications of theapparatus employed in a shaft sinking operation.

FIGS. 1 to illustrate the preferred modifications of the improvedapparatus for performing the novel method of excavating a preliminarypilot hole 19 which may be extended to the full distance of a proposedshaft 12, as illustrated in FIGS. 6 to 10, before the actual shaftsinking operation starts or which may be advanced in increments of suchlength so that in either of the modifications the pilot hole will bemaintained in advance of a working face 14 of the shaft 12. a sutficientdistance to provide a loading zone such as a skip pocket 16 in advanceof the working face 14 of the shaft 12, in a manner to be explained inmore detail hereinafter. An open ended casing 18 which defines a skipwayshaft 29 i positioned within the pilot hole 1% and in accordance withthe modification of this invention as illustrated in FIGS. 1 and 2 thecasing 18 is in the form of a cutter casing 22 and the pilot hole 10 isexcavated, dug, sunk or drilled by rotating the cutter casing 22 havinga cutter.

head 24 which includes a cutter device 26 which may be in the form ofserrated cutter blades 28 disposed in the lower portion of the rotatingcutter casing 22 in spaced relationship to each other, note FIG. 2. Thelower end portion of the cutterhead 24 is provided with a plurality ofgenerally radially disposed elongatedcirc'umferentially spaced slots 39which enable cuttings material that is excavated by the cutter-head 24to pass generally axially through the lower open end portion of thecutter casing 22. Suitable cutter casing rotating drive and feed means,not illustrated, is provided on ground surface S for rotating the cuttercasing 22.. The casing 18 extends generally vertically and terminatesupwardly beyond the ground surface S a sufiicient distance to define anunloading zone and enable a suitable skip dump 32,,note FIGS. 11 and 12,to be provided so that the material which is excavated may be readilyremoved to and disposed of on the ground surface S.

Within the rotating cutter casing 22 there is provided a suction pump orbailer type skip 34 which includes a skip housing orrcylinder 36, pistonrod .38 and bailing piston 40 having suitable packing means 42. Attachedto the upper end portion of the piston rod 38 is a weight 44 and a skiphoist cable 46. which is attached to any conventional type of hoistingsystem, not illustrated, which is positioned on the ground surface S forraising and lowering the skip 34 between the skip pocket 16 at theloading zone and the skip dump 32. at the unloading zone,as desired.

The lower end portion of the skip housing 36 is provided with aplurality of spaced openings 48 which overlie in registration with theslots 39 in the cutterhead 24 and one way check type flap valve means 50may be pivotd ally mounted or hinged to the lower end portion of theskip housing 36 for closing the openings '48 and to enable cuttingsmaterial which is excavated by the cutterhead 24 to move into the skip'54 on the upward stroke of the bailing piston 4%.

It is to be noted that the rotating cutter casing 22 is of smallerdiameter than the diameter of the pilot hole 10 which is cut by thecutterhead 24 so that there is provided an annular generally cylindricalspace 52 between the pilot hole 10 and the rotating cutter casing 22. Aconduit :74 which is connected to a water supply such as a reservoir orthe like, not illustrated, is in communication with the space 52 througha water supply collar 56 so that water may be flushed and flow downbetween the cutter casing 22 and the pilot hole 10 into the space 52 tofacilitate the removal of the cuttings material which has been excavatedby the cutter head 24 so that on the upward roke of the bailing piston49 the flushing water and cuttings material are flushed into the skip 34through the open slots 30, openings 48 and the valve means 50 and uponfilling of the skip 34 with the flushing water and cuttings material thevalve means 50 normally closes to retain the material within the skip'34 and the skip 34 may then be raised to the skip dump 32 by means ofthe skip hoist cable 46 of the hoisting system and then dumped.

In operation, the cutter casing 22 of the apparatus of the modificationillustrated in FIGS. 1 and 2 is rotated by the drive and feed means, notillustrated, to operate the cutter blades 28 of the .cutterhead 24 andthe flushing water flowing down around the outer surface of the cuttercasing 22 in the space 52 will wash and urge the cuttings material upthrough the open slots 36, openings 48 past the valve means 50 into theskip 34. When the skip 34 is lowered to the loading position in thelower end of the cutter casing 22 the hinged valve means 50 encountersthe cuttings material that has accumulated at the bottom of the cuttercasing 22 and the skip housing 36 may or may not sink and slide downaround such cuttings material. In any event, when the skip housing '36comes to rest, the weighted piston rod 38 and bailing piston 40 continueto move downwardly and descend until contact is made with the bottom ofthe skip housing 36, the valve means 50 or the accumulated cuttingsmaterial, as the situation may be. The hoist cable 46 is then pulledupwardly to raise the piston rod 38 and bailing piston 40 and cause anupward flow of the flushing water and cuttings material through theslots 30, openings 48 and valve means 50 into the skip housing 36. Asthe cuttings material moves into the skip housing 36 the skip 34generally sinks and thus facilitates the loading operation. When thepiston rod 33 and bailing piston 49 reach the upper limit of travel, theskip 34 is raised by the hoist cable 46 of the hoisting system and thecuttings material is trapped within the skip housing 36 above the hingedor pivoted valve means 50. The skip 34 is raised while the cutter casing22 continues to rotate and the skip 34 is lowered to the bottom and theoperation cycle is repeated.

Attention is now directed to FIGS. 3 to 5 wherein there is illustrated amodification of the improved apparatus for performing the novel methodof digging, sinking, drilling or excavating the pilot hole 10. In thismodification the casing 18 which defines the skipway shaft 20 is anonrotating casing 58 that is clamped through suitable collar clampingmeans, not illustrated, at the ground surface S with the casing 58 beingof smaller diameter than the pilot hole dtl to define the annular space52 between the pilot hole 10 and the casing 58 with the conduit means 54being in communication with the space 52 through the collar 56. Arotating skip 60 is positioned within the casing 58 and includes a skiphousing 62 having a cutterhead 64 in the form of an enlarged threebladed auger type bit 66 without spiral flights having a plurality ofspaced generally radially disposed openings 68 in the lower end portionthereof. Circumferentially spaced intermediate the blades of the bit 66there are provided hinged gage cutters 70 which extend generallyradially outwardly from the periphery of the skip housing 62. Ifdesired, one way flap valve means 72 may be provided for the lower openend of the cutterhead 64.

In this modification of the apparatus, since the cutterhead 64- islocated on the lower end portion of the rotating skip 66 and since theskip 69 is positioned within the casing 58 and further, since it isdesirable that the pilot hole It be larger than the casing 58 to definethe space 52 therebetween, the gage cutters 70 are each hingeablymounted to the skip housing 62 by suitable means such as pins 7 4 sothat the gage cutters 7 0 will normally swing inwardly relative to thecasing 58 so that the rotating skip 60 may be raised and lowered betweenthe loading and unloading zones through the skipway shaft defined by thecasing 58.

The gage cutters 7i? are hingeably carried by the skip housing 62 sothat the cutters 7% will hang generally downwardly a sufiicient amountto clear the casing 58 during movement of the skip fill therein and whenthe skip 60 descends the cutters 70 will be urged outwardly to thecutting position by reason of the weight of the skip. The skip 60 isrotated within the casing 58 through a drive bar 76 which extends beyondthe ground surface S and terminates in a suitable connection to arotating drive means, not illustrated.

On rotation of the skip 60 through the drive bar 76 the cutterhead 64removes material from the bottom of the pilot hole 10 and the cuttingsmaterial and flushing Water are permitted to enter and fill the rotatingskip 60 through the openings 68 of the cutterhead 64 and when the skip60 is filled it is hoisted to the skip dump 32 on the ground surface Sby means of suitable hoisting apparat-us, not illustrated.

In each of the modifications of the improved apparatus for performingthe novel method of excavating the pilot hole 10, described above andillustrated in FIGS. 1 to 5, the flushing of the water through theannular space 52 and the slots and openings 43 and 68 of the skips 34and 60, respectively, provides a hydraulic head or a difference ofpressure between the outside of the casings 22 and 58 and the inside ofthe respective skip 34 or 60 which is effective in moving and conveyingthe cuttings material into the respective skip for haulage to the skipdump 32.

If desired, a centrifugal pump or reciprocating sand pump, neither beingillustrated, may be employed at the bottom of the casing to aid in theremoval of the flushing water and cuttings from the bottom of the pilothole 16 to the ground surface S.

Further, some survey or control should be made during the excavating ofthe pilot hole It but it is not necessary that the pilot hole bemaintained on center relative to the proposed shaft 12 and the pilothole It) may be oif center, to some degree, and still serve as a shaftguide for the proposed shaft 12 by employing a casing 18 for the skipwayshaft that is substantially smaller in crosssectional area than thepilot hole 10 and an eccentric guide for adjusting the skipway shaftwithin the pilot hole Ill.

In practicing the improved method of shaft sinking in accordance withthis invention, after the pilot hole It) has been excavated to a desireddistance, that is, either to the entire depth of the proposed shaft 12or at least to a distance so that the pilot hole 10 will define theloading zone or skip pocket 16 in advance of the shaft working face 14,the ground material which surrounds the casing 18 and which is disposedimmediately laterally adjacent to or radially outwardly from the skipwayshaft 20 intermediate the end portions thereof is removed by suitableexcavating, cutting, and/or conveying means 80 to be described anddisclosed in more detail hereinafter, so that the pilot hole 10 isexpanded in a generally lateral direction, to a desired cross-sectionalarea with the result being that the proposed shaft 12 is continuouslyadvanced by first, excavating the pilot hole 1% in a given directionindicated by the arrows A, note FIGS. 7, 9 and 10, to a desired distanceand then continuously advancing'the shaft working face 14 in the samegeneral direction, as indicated by the arrows B.

"in practice, it has been found most desirable to have the pilot hole 10of approximately 6 to 8 feet in diameter and it is possible to easilyexpand such pilot hole to a diameter of at least 60 feet, or larger ifdesired, to define the confines of the shaft 12.

For the sake of brevity, in describing and disclosing the variousmodifications in the method and apparatus for expanding the pilot hole10, as illustrated in the FIGS. 6 to 10, the casing 18 which defines theskipway shaft 26 and a skip 82 will be indicated by similar and likereference characters, respectively, throughout the several views. It isto be understood that in the modifications of the improved method andapparatus as disclosed, described and illustrated, that the skip 82 maybe of any suitable and desired structure and while the skip isillustrated as a common bottom dump type skip, FIGS. 6 to 12, bail typeskips 34, FIGS. 1 and 2 and a rotary skip 60, FIGS. 3 to 5, the skip mayalso take other conventional forms.

In each modification the casing 18 will not only act as a skipway shaft20 through which the skip 82 may be hoisted but will also provideprotection for men who may be working in the shaft 12. It is to be notedthat in each of the modifications of the improved method and apparatusfor expanding the pilot hole 10 as illustrated in FIGS. 6 to 10 that thecasing 18 is provided with a plurality of laterally extendingcircumferentially spaced openings 84 through which the generallyradially or laterally outwardly disposed ground material is passed fromoutside the respective casing 18 to within the casing and into therespective skip 82 for hoisting to the unloading zone at the skip dump32 on the ground surface S. It is also to be noted that, as illustrated,the casing 18 includes a series of easing sections and that in thevarious modifications of the improved method and apparatus the casing 18is illustrated as including a lower section 86 and an upper section 83.If the pilot hole 10 is extended substantially simultaneously with theadvance of the shaft working face 14, the lower section 86 of the casing18 is provided with the plurality of openings 84 through which thecuttings material is conveyed to the skip 82 in the loading zone at theskip pocket 16 and in this instance, the openings 84 are disposed inlongitudinal registration with the working face 14 in a position toreceive the cuttings material since the openings 84 are in the lowersection 86 of the casing 18 which is advanced with the advancement ofthe shaft working face 14. If the pilot hole 10 is excavated tosubstantially the entire depth of the proposed shaft 12 prior to theexpansion of the pilot hole 10 then it is. possible to pull the pilothole excavating casing and add the lower section 86, having the openings84 therein, and then replace the casing 18 and advance same with theadvance of the shaft working face 14 during the expansion of the pilothole ltl. it is also possible, if necessary, to provide the pilot holeexcavating casing with a plurality of the openings 84 with the openingsbeing circumferentially and longitudinally spaced throughoutsubstantially the entire longitudinal extent of the casing so that oncompletion of the pilot hole Ill it would not then be necessary to pullthe entire casing 18 and the excavation operation in expanding the pilothole 10 would be elfective since there would be openings 84 at any depthwhich would be in registration with the advance of the shaft workingface 14.

In the modification of the improved apparatus for performing the novelmethod of sinking the shaft 12, as illustrated in FIGS. 6 to 8, theexcavator-conveyor means 89 is generally horizontally disposed andextends generally radially or laterally outwardly relative to the casing13. The excavator-conveyor means 80, as illustrated, is mounted to thecasing 18 by an apron guide 90 so that the excavator-conveyor means 351may move circumferentially or peripherally around the casing 18 asindicated by the arrows in FIG. 89, as illustrated, includes a screwconveyor 92 and a cutter chain 94 is provided. in advance of the screwconveyor 92 for cutting, excavating or removing the ground material fromthe working face 14 of the shaft 12.' In this modification the conveyorapron guide 99 enables the cutter chain 94- and the screw conveyor 92 tohave helical movement relative to the longitudinal axis of the casing18, note the shaft bottom and working face 14 as illustrated in FiG. 7.'

Inthis modification, it is possible for the casing 18 to be eitherrotating as the cutter casing 22 above described and illustrated inFIGS. 1 and 2 or non-rotating as the casing 58 above described in FIGS.3 to 5. In each instance either rotating or non-rotating casings whichexcavate the pilot holelt), the excavator-conveyor means 39 is rotatedin the helical path relative to the longitudinal axis of the casing 18to effect the desired excavation or cut. In the modification asillustrated in FIGS. 6 to 8 of the drawing, the casing 18 does notrotate and would correspond to the apparatus and method for excavatingthe pilot hole 10 as described and disclosed above and illustrated inFIGS. 3 to 5.

Intermediate the cutter chain 94 and the screw conveyor 92 there isprovideda conveyor apron $6 which enables the cuttings material to beeasily moved from the shaft working face 14 into proximity with thescrew conveyor 96 so that the cuttings material may be moved toward thecasing 18 through the openings 84 and into the skip 82. Theexcavator-conveyor means St? is driven in the helical path by a motorand suitable gearing means 98 which includes a spiked apron drive wheel99 that is in engagement with the shaft bottom for moving theexcavator-conveyor means 80 into operative position relative to thegenerally vertically disposed shaft working face 14. Also, the motor 98is utilized to drive the screw conveyor 92 through suitable gearing(FIG. 6) and to drive the cutter chain 94 through any suitable drivingconnection (not shown). The helical path through which theexcavator-conveyor means 80 progresses in expanding the pilot hole 1%?is a path that is circumferentially around the casing 13 andsimultaneously longitudinally downward relative thereto. The improvedapparatus of this modification provides a generally vertically disposedworking face 14 from which the ground material may be readily removedand while the screw conveyor 92 and the cutter chain 94 have beenillustrated as the excavator-conveyor means 84) in this modification,his to be understood that other conventional types of excavators such aspick and shovel, pneumatic hammers, power spades, mechanical boringapparatus, rotating disk cutter bars, etc. and other conventional typesof conveying means or systems such as belt conveyors, hydraulic systems,etc. may be used to expand the pilot hole 16' to the desired size andthe screw conveyor 92 and cutter chain 94- have been disclosed for thepurpose of illustration only. By employing the substantiallyhorizontally disposed generally radially extending excavator-conveyormeans 80 which moves in the helical path around the casing 18 theworking face 14 and the spiral shaft bottom are advanced by excavatingthe generally vertical working face 14 slightly below the previous outwhich is considerably faster and cheaper than removingmaterial from asubstantially horizontally disposed shaft bottom.

Attention is now directed to FIG. 9 wherein there is shown amodification of the improved apparatus for performing the novel methodof expanding the pilot hole 10 to the desired size in sinking the shaft12, or the like, which is preferably used in combination with themodification of the method and apparatus illustrated in FIGS. 3 to 5,described and disclosed above, wherein the cas- 6. Theexcavator-conveyor means ing 18 is non-rotating. .In this modification,a suitable head frame 1%, FIG. 11, is provided for supporting the casing18 and the excavating means which is, in this modification, in the formof a cutterhead 102 including cutter bars 194 having rotating cutters106. The cutter bars 1&4 are inclined and converge toward the pilot hole1% in the direction of advance of the shaft working face 14 so that theshaftworking face is in the form of an inverted cone. The cutterhead1tl2 rotates about the lower section 86 of the casing 18 and issupported therefrom by suitable cutterhead guide bearing means 108. Athrust collar 11% is provided on the lower section 86 of the casing 18for supporting a non-rotating cutterhead support structure 112. Acutterhead drive motor 114 is supported on the support structure 112 andis operatively connected through suitable thrust rollers and gears 116for rotating the cutterhead 102. A cutterhead hoist 118 is supported onthe support structure 112 for operatively maneuvering the cutterhead 102relative to the shaft working face 14 with the hoist 118 being connectedto the cutterhead 102 through suitable sheave and cable means 126 whichis secured to a ground supported structure 122.

The head frame structure 100, as illustrated in FIG. 11, is preferablyused in combination with the modification of the improved method andapparatus as shown in FIG. 9 wherein the casing 18 is non-rotating, andincludes a tripod type derrick frame structure 124 which has a skiphoist sheave 126 positioned at the apex thereof about which the hoistcable 46 passes with the hoist cable being connected between the skip 82and a skip hoist 128 supported on a hoist operating platform 130. Inthis modification of the head frame structure 100, the upper sec tion 88of the casing 18 is supported through an upper support collar 132 whichis supported upon the hoist operating platform 130 with the supportcollar 132 arranged to permit sliding adjustment for guiding the lowersection 86 of the casing 13 and the cutterhead 102. The lower section 86is disposed in telescopic relationship with the lower end of the uppersection 88 and suitable guide collar means 134 is provided for thetelescoping upper and lower sections 88 and 86. A clamp collar 136 joinsthe telescoping casing sections 86 and 88 and a suitable counterweight138 is provided for the lower section 86. It is to be understood thatadditional lower skipway sections 86', shown by dotted lines, may beadded to the casing 18, in any well known manner, as required during theadvancement of the pilot hole '10. The skip 82 is illustrated in solidlines in FIG. 9 as being in the loading zone at the skip loadingposition in the skip pocket 16 and in dotted lines in FIG. 11 as beingin the unloading zone at the skip unloading position in the skip dump 32wherein the cuttings material which has been removed during theadvancement of the shaft 12 may be dumped from the skip 82 which ispositioned in the upper casing section 88 with the material passing intoa chute 140 through a skipway chute gate 142 having a weighted lever 144thereon. Suitable telescoping cutterhead torque arms 146 may be clampedand positioned between the cutterhead support structure 112 and the wallof the shaft 12 to provide suitable support as excavating of the shaftadvances.

It is to be noted that in the modification of the improved method andapparatus as illustrated in FIGS. 9 and 10 that the shaft working face14 of the shaft bottom is inclined to the vertical and is substantiallyconical in configuration with the apex thereof extending downwardly inthe direction of advancement of the excavation of the shaft 12 so thatthe shaft working face 14 converges toward the pilot hole 10 and thecasing 18 in the direction of advancement to facilitate in the movementof the cuttings material which is cut by the cutterhead 102 through theopenings 84 in the casing 18 for easy loading into the waiting skip 32which is positioned in the skip pocket 16. r

Attention is now directed to the modification of the improved apparatusfor performing the novel method of exca vating, sinking or driving theshaft as illustrated in FIG. wherein the primary difference between thismodification and the modification as illustrated in FIG. 9, as disclosedand described above, is that the casing 18 rotates and the instantmodification is preferably used in combination with that modification ofthe method and apparatus for excavating the pilot hole 10 as illustratedin FIGS. 1 and 2 described and disclosed above. In order to enable thecasing 18 to rotate, there is provided a flanged portion 148 on theupper end of the lower casing section 86, see FIG. 12, and a cutterheaddrive gear 150 is bolted to the flange 148 of the lower section 86.Suitable thrust rollers 152 support the lower section 86 of the casing18 and the cutterhead 102 and the thrust rollers 152 are in turnsupported through a support structure 154 which includes a cutterheaddrive frame 156 that is longitudinally moveable in the direction of thearrow relative to the casing 18 by means of a slotted guide frame 158.The cutterhead drive frame 156 has an open portion 160 that permits theadditional sections 86 to be added to the casing, as needed. The slottedguide frame 158 takes the cutting torque reaction Which is createdthrough the rotation of the casing 18 and cutterhead 102. During thesinking of the shaft 12 by expanding the pilot hole 10 the cutter driveframe 156 moves between the upper position, as illustrated by the solidlines of FIG. 12, to a lower position adjacent the ground surface S andwhen the cutter drive frame 156 reaches the lower position, the lowercasing section flange 148 is released from the lower section of thecasing 18 and the cutter drive frame 156 is raised to the upper positionand the additional section 86' of the casing is added as requiredthrough the advancement of the shaft working face 14. As shown in FIG.10 the cutterhead 102 is supported for rotation with the lower section86 of the casing 18 by means of a cutterhead supporting structure 162having a collar 164 which is clamped to the lower section 86 forrotation therewith. As illustrated, a non-rotating work platform 166 issecured to the wall of the shaft 12 through suitable anchoring boltmeans 168 and supporting rollers 170 support the work platform 166 onthe cutterhead supporting structure 162. A cutterhead and casing drivemotor 172 is carried by the cutter drive frame 156 and the drive motoris operatively connected to the drive gear 150 to rotate the casing 18and cutterhead 102. The advancement of the cutterhead 1112 and thepositioning of the lower section 86 of the casing 18 and cutterhead 102are controlled through a cable system 174 which is secured to the cutterdrive frame 156 and is operative in response to a hoist 176.

In each of the modifications of the apparatus and method of shaftsinking as described above and illustrated in FIGS. 6 to 10 it is to beunderstood that if flushing water is used in the excavating of the pilothole 10 simultaneously with the expansion of the pilot hole to thedesired shaft size, the level of such flushing water is maintained belowthe shaft working face 14 and that the flushing water is fed into thespace 52 by suitable conduit means at a level below the openings 84 inthe casing 18. Since the apparatus for feeding flushing water to thespace 52 when the pilot hole 10 is excavated simultaneously withexcavation of the shaft 12, forms no part of the instant invention, itis not disclosed herein. It is contemplated herein, therefore, that theexcavation operation of the ground material which surrounds the casing18 be performed with the pilot hole 10 being dry.

From the above description and disclosure, it is to be understood thatin practicing the method of this invention that the apparatus may beused in various combinations which are generally related to the type ofground or material through which the shaft is being sunk and also towhether the method employs the sinking of the pilot hole 10 to theentire distance of the proposed shaft or whether the pilot hole 10 willonly be in advance of the shaft working face 14 a sufficient distance toprovide the skip pocket 16 and that certain features of the improvedapparatus for performing the method of this invention may beinterchanged with the corresponding apparatus illustrated in the othermodifications.

While the invention has been described in terms of a number ofarrangements and embodiments, the scope of the invention shall not bedeemed to be limited .by the embodiments and arrangements as hereinshown, such other embodiments and arrrangements being intended to bereserved especially as they fall Within the scope of the claims hereappended.

I claim as my invention: 1. Apparatus for enlarging the cross-sectionalarea of an existing pilot hole,

said apparatus comprising, in combination, an elongate open ended casinghaving a length greater than the depth of such pilot hole,

means supporting the casing with one end portion extending into suchpilot hole with the other end portion thereof projecting above groundsurface to define a continuous passageway from such pilot hole to groundsurface,

said casing having a plurality of generally lateral openings disposedintermediate the end portions thereof at a location therealong which isspaced from the one end portion thereof a distance which is sufiicientto define a loading zone therein,

excavating means carried by the casing and disposed thereon adjacent thelateral openings therein and projecting laterally outwardly therefromfor removing at least that portion of ground material which surroundsthe casing intermediate the end portions thereof to expand the area ofsuch pilot hole,

said excavating means being effective to remove such portion of groundmaterial and enable same to pass through the lateral openings in thecasing to the loading zone therein, and

means for removing the excavated portion of such ground material fromthe loading zone to an unloading zone at ground surface,

said last mentioned means being entirely disposed within the confines ofthe casing and movable through the passageway defined thereby throughoutsubstantially the full longitudinal length thereof between the loadingand the unloading zones.

2. The apparatus as set forth in claim 1, together with means forrotating the excavating means relative to the casing.

3. The apparatus as set forth in claim 1 wherein the excavating means isdisposed relative to the casing to create a working face which has asurface that is inclined relative to the casing.

4. The apparatus as set forth in claim 1 wherein said casing comprises aplurality of substantially cylindrical sections with adjacent ones ofsaid sections being disposed in end to end relationship relative to eachother.

5. The apparatus as set forth in claim 4 wherein that section of thecasing which is at the other end portion thereof is supported totelescopically receive that section of the casing which is immediatelyadjacent thereto, and

that section of the casing which is at the one end portion thereof isprovided with the lateral openings.

References Cited by the Examiner UNITED STATES PATENTS 1,033,990 7/12Connolly 175--l61 1,516,830 11/24 Schafer 262-5 1,834,751 12/31 Upson61-40 2,000,195 5/ 35 Siebel 61-57 X (Gther references on followingpage) 1 1 UNITED STATES PATENTS Satre 61- -53.64 Berlin 61--40 Smith,6153;64

Catland 175344 Love 175344 Wick 614O Sewell 175--309 Thornley 6140Gregory 175-309 Long 175--57 Van Dusen 21417 FOREIGN PATENTS Germany.France. France.

Great Britain. France.

OTHER REFERENCES German printed application (Meininghaus),- 16,183,

1. APPARATUS FOR ENLARGING THE CROSS-SECTIONAL AREA OF AN EXISTING PILOTHOLE, SAID APPARATUS COMPRISING, IN COMBINATION, AN ELONGATE OPEN ENDEDCASING HAVING A LENGTH GREATERR THAN THE DEPTH OF SUCH PILOT HOLE, MEANSSUPPORTING THE CASING WITH ONE END PORTION EXTENDING INTO SUCH PILOTHOLE WITH THE OTHER END PORTION THEREOF PROJECTING ABOVE GROUND SURFACETO DEFINE A CONTINUOUS PASSAGEWAY FROM SUCH PILOT HOLE TO GROUNDSURFACE, SAID CASING HAVING A PLURALITY OF GENERALLY LATERAL OPENINGSDISPOSED INTERMEDIATE THE END PORTIONS THEREOF AT A LOCATION THEREALONGWHICH IS SPACED FROM THE ONE END PORTION THEREOF A DISTANCE WHICH ISSUFFICIENT TO DEFINE A LOADING ZONE THEREIN, EXCAVATING MEANS CARRIED BYTHE CASING AND DISPOSED THEREON ADJACENT THE LATERAL OPENINGS THEREINAND PROJECTING LATERALLY OUTWARDLY THEREFROM FOR REMOVING AT LEAST THATPORTION OF GROUND MATERIAL WHICH SURROUNDS THE CASING INTERMEDIATE THEEND PORTIONS THEREOF TO EXPAND THE AREA OF SUCH PILOT HOLE, SAIDEXCAVATING MEANS BEING EFFECTIVE TO REMOVE SUCH PORTION OF GROUNDMATERIAL AND ENABLE SAME TO PASS THROUGH THE LATERAL OPENINGS IN THECASING TO THE LOADING ZONE THEREIN, AND MEANS FOR MOVING THE EXCAVATEDPORTION OF SUCH GROUND MATERIAL FROM THE LOADING ZONE TO AN INLOADINGZONE AT GROUND SURFACE, SAID LAST MENTIONED MEANS BEING ENTIRELY DISPOEDWITHIN THE CONFINES OF THE CASING AND MOVABLE THROUGH THE PASSAGEWAYDEFINED THEREBY THROUGHOUT SUBSTANTIALLY THE FULL LONGITUDINAL LENGTHTHEREOF BETWEEN THE LOADING AND THE UNLOADING ZONES.